Question

这可能是一个非常小的问题，但我仍然无法找到解决方案。我正在使用Apace Tomcat 7.0.54和JAVA 1.7

我在创建html页面的网页中收到以下错误，并在web.xml中添加了servlet名称和URL映射

 Error message:
 HTTP Status 404 - /sayhello/
 type Status report
 message /sayhello/
 description The requested resource is not available.

以下是我的JAVA代码。

// To save as "<TOMCAT_HOME>\webapps\hello\WEB-INF\classes\HelloServlet.java"
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class HelloServlet extends HttpServlet {
   @Override
   public void doGet(HttpServletRequest request, HttpServletResponse response)
         throws IOException, ServletException {

      // Set the response MIME type of the response message
      response.setContentType("text/html");
      // Allocate a output writer to write the response message into the network socket
      PrintWriter out = response.getWriter();

      // Write the response message, in an HTML page
      try {
         out.println("<html>");
         out.println("<head><title>Hello, World</title></head>");
         out.println("<body>");
         out.println("<h1>Hello, world!</h1>");  // says Hello
         // Echo client's request information
         out.println("<p>Request URI: " + request.getRequestURI() + "</p>");
         out.println("<p>Protocol: " + request.getProtocol() + "</p>");
         out.println("<p>PathInfo: " + request.getPathInfo() + "</p>");
         out.println("<p>Remote Address: " + request.getRemoteAddr() + "</p>");
         // Generate a random number upon each request
         out.println("<p>A Random Number: <strong>" + Math.random() + "</strong></p>");
         out.println("</body></html>");
      } finally {
         out.close();  // Always close the output writer
      }
   }
}

Web.xml中

<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app version="3.0"
  xmlns="http://java.sun.com/xml/ns/javaee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">

   <!-- To save as "hello\WEB-INF\web.xml" -->

   <servlet>
      <servlet-name>HelloWorld</servlet-name>
      <servlet-class>HelloServlet</servlet-class>
   </servlet>

   <!-- Note: All <servlet> elements MUST be grouped together and
         placed IN FRONT of the <servlet-mapping> elements -->

   <servlet-mapping>
      <servlet-name>HelloWorld</servlet-name>
      <url-pattern>/sayhello</url-pattern>
   </servlet-mapping>

</web-app>

这里应该纠正什么？还有一件事，我也试过执行另一个JAVA数据库servlet。它也没有返回任何内容并给了我同样的错误。

Answer 1

正如您所说，您将网址设为localhost:8080/sayhello

试试这个网址http://localhost:8080/projectName/sayhello

Answer 2

您在网址中缺少项目名称/上下文路径：

http://localhost:8080/ProjectName/sayhello

Answer 3

您的<Servlet-class>值是否属于任何包裹？如果是，然后给出“PackageName.ServletClassName”。如果不是尝试的话以http://localhost:8080/ProjectName/sayhello开头。如果是不是问题尝试更改端口（8080）（右键单击 server-＆gt; properties-＆gt;切换位置。）。在服务器目录下单击属性并在服务器位置下尝试更改为“使用 tomcat安装“。尽量保持index.html不仅在web-inf中而且还在在web内容文件夹中也是（如果你有index.html文件）。

HTTP状态：404 - Java Servlet

3 个答案: